Tunneling shield

ABSTRACT

A tunneling shield is provided having a hull section positioned along the bore of the tunnel. The hull section includes a plurality of movable hollow hood segments having closed forward ends mounted around the upper periphery thereof. The hollow hood segments have sufficient beam and columnar strength to resist deflections as the hood segments are moved forward to provide a shield under which excavation may occur. The hood segments are mounted between divider plates having ways or slides for facilitating the movement of the hood segments without deflection.

United States Patent [72] lnventor Richard W. Stevens 834,745 10/1906 Moir 61/85 Oconomowoc, Wis. 2,208,608 7/1940 Stanley... 61/85 [21] Appl. No 839,577 3,306,055 2/1967 Tabor..... 61/85 [22] Filed July 7,1969 3,325,217 6/1967 Enz i 299/33X [45] Patented June 1, 1971 3,339,980 9/1967 Winberg 299/33 [73] Assignee Milwaukee Boiler Manufacturing Company 3,378,305 4/1968 Geldmacher et a1 61/85X Milwaukee, Wis.

Przmary Examiner-Dennis L. Taylor Attorney-Danie] D. Fetterley [54] TUNNELING SHIELD 7 Chums 7 Drawmg ABSTRACT: A tunneling shield is provided having a hull sec- [52] US. Cl 61/85 {ion positioned along the bore of the tunnel, The hull section lllt- Cl 8 includes a plurality of movable hollow hood segments having [50] Field Of Search 61/85, 84, closed forward ends mounted around the upper periphery 42, 299/33, 1 1 thereof. The hollow hood segments have sufficient beam and 56 R f ed columnar strength to resist deflections as the hood segments 1 e erences n are moved forward to provide a shield under which excavation UNITED STATES PATENTS may occur. The hood segments are mounted between divider 91,071 6/ 1969 Beach 61/85 plates having ways or slides for facilitating the movement of 834,732 10/ 1 906 .lapp 61/85 the hood segments without deflection.

PATENTEDJUN nan 3581' sum 2 or 3 IN VliN 'IOR.

PATENTED JUN 1:971 358L507 sum 3 nr 3 /fl6 L BY 110/110 M Jinn/.5

0 vim TUNNEILING SHIELD BACKGROUND OF THE IVENTIONDESCRIPTION OF THE PRIOR ART Tunneling shields have heretofore been employed to drive tunnels through running" or bad ground which is incapable of excavation without subsidence. Running ground which is incapable of excavation without subsidence. Running ground may comprise dry running sand, sand mixed with gravel or boulders, gravel and boulders alone, or wet loose sand.

Such tunneling shields include a hull section which is placed ahead of the tunnel liner in the bore of the tunnel. A movable shield or hood, generally comprised of a plurality of movable poling plates, or segments, is mounted along the upper edge of the hull section. Prior to commencing excavation, the poling plates are extended into the running ground at the tunnel work face by hydraulic, mechanical or other means. The ground beneath the poling plates may then be excavated rapidly and safely as the poling plates support the running ground, preventing the unwanted subsidence of the soil. The excavated soil is removed through the hull section and tunnel liner.

When the area beneath the poling plates has been completely excavated, the hull section is advanced into this area by mechanical or hydraulic means bearing on the tunnel liner. A new section of the tunnel liner is inserted along the tunnel bore in the space formerly occupied by the hull section. The above operation of the tunneling shield is then repeated to extend the tunnel.

Because of the safety and speed with which tunnels may be bored by the use of tunneling shields, it has become apparent that they may be used to advantage in boring tunnels through rock and compacted ground which may be subject to the same faults as running ground. The shield with the poling plates retracted is placed against the working face of the tunnel. After the blasting necessary to loosen the rock, the poling plates are extended to provide protection to the workmen removing the blasted rock. The tunneling shield is then advanced in the manner described supra.

While prior art tunneling shields have operated in a generally satisfactory manner, their operation has been subject to several shortcomings. To ease the insertion of the plates into the ground, they were generally constructed of sheet material. While such plates could be driven into the ground with facility, they tended to fold over each other or to break. Such plates were also easily deflected by boulders or the like in the ground. This has, in the past, been overcome by providing an upthrust to the plates from the hydraulic or mechanical means used to advance the plates. However, both the upthrust on the plates and their deflection have tended to cause the tunneling shield to turn from the desired course. Furthermore, such tunneling shields were often incapable of tunneling through rock because the flying rock caused by the blasting damaged the exposed hydraulic or mechanical mechanisms in the hull section.

Other prior art tunneling shields have attempted to avoid the problems associated with the movable poling plates by incorporating a fixed hood on the forward edge of the hull section and advancing the entire structure by means of hydraulic jacks bearing on the tunnel liner. However, tunneling shields of this type have proven inflexible in operation and possessed of great tendency to deflect from the true course of the tunnel.

SUMMARY OF THE PRESENT INVENTION It is, therefore, the object of the present invention to provide an improved tunneling shield which overcomes the aforesaid shortcomings of prior art tunneling shields.

Specifically, it is the object of the present invention to provide an improved tunneling shield wherein the hood segments of the shield comprise members having sufficient beam and columnar strength to prevent deflection or breakage of the segments when they are extended.

It is a further object of the present invention to provide an improved tunneling shield in which the hood segments are mounted on the hull section of the tunneling shield in a manner which supports the hood segments during their extension so as to prevent their deflection.

A still further object of the present invention is to provide a tunneling shield in which the mechanism for extending the hood segments is protected when the hood segments are retracted thereby permitting the exposure of the tunneling shield during rock blasting without damage to the mechanism.

The present invention provides a tunneling shield having a longitudinally extending hull section for lying along the bore of the tunnel when in use. A segmented hood is mounted on the forward end of the hull section for abutting the working face of the tunnel. The hood comprises a plurality of longitudinally movable, laterally adjacent hood segments positioned on the hull section.

The hood segments are hollow so that the hydraulic cylinders for extending and retracting the hood segments may be mounted inside the segments in a protected manner.

The hood segments are constructed so as to have a beam and columnar strength sufficient to resist deflection as the hood segments are extended.

The hood segments are mounted on the hull section between divider plates having slide means for assisting in the extension of the hood segments and for further preventing deflection of the hood segments.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a perspective view of the tunneling shield of the present invention with an adjacent portion of the tunnel liner shown in phantom;

FIG. 2 is a longitudinal cross-sectional view of the tunneling shield of the present invention showing the hood segments of the shield in the retracted position, the extended position of the hood segments being shown in phantom;

FIG. 3 is a partial longitudinal cross-sectional view of the hull section of the tunneling shield showing construction details thereof;

FIG. 4 is a front view of the tunneling shield as seen by an observer positioned along line 4-4 of FIG. 2

FIG. 5 is a lateral cross-sectional view of the tunneling shield taken along the line 5-5 of FIG. 2;

FIG. 6 is a partial lateral cross-sectioned view taken along the line 614 6 of FIG. 2 showing details of the hood segments; and

FIG. 7 is a schematic diagram of a hydraulic circuit suitable for operating the hydraulic cylinders of the tunneling shield.

DESCRIPTION OF THE PREFERRED EMBODIMENT Turning now to the figures, tunneling shield 10 of the present invention is shown in FIGS. 1 and 2 thereof, in conjunction with a section of tunnel liner 12. The latter element is adapted to lie along the bore of the tunnel so as to provide a lining having sufficient strength to resist the compressive or crushing forces applied thereto by the surrounding soil. For this purpose, a plurality of internal braces 14 are provided in tunnel liner 12, as shown in FIG. 2. The tunnel liner may be circular in cross-sectional configuration but is preferably of the same general horseshoe-shaped cross-sectional configuration as tunneling shield 10, shown in FIG. 4, wherein a flat portion 16 forms a floor for the workmen in the tunnel liner. Both tunneling shield 10 and tunnel liner 12 may be of any desired cross-sectional size and are usually sufficiently large to permit men to work therein in relative ease.

Tunneling shield 10 is adapted to be positioned on the forward end of tunnel liner 12 so as to be against the work face of the tunnel. Tunneling shield 10 is comprised of two main elements: a hull section 18 and relatively movable hood or shield 20 mounted thereon.

Hull section 18 is essentially a tubular member of the same cross-sectional configuration as tunnel liner 12. In the present exemplary instance, hull section 18 is formed of a horseshoeshaped outer surface plate 22 and a floor 24.

The portion of bull section 18 adjacent tunnel liner l2 supports a plurality of hydraulic cylinders 26 which are used to move tunneling shield forward, with respect to the tunnel liner 12, in a manner hereinafter described. For this purpose, a central rib, or partial bulkhead, 28 is provided, which extends inwardly from surface plate 22. A rear rib 30 likewise extends inwardly from surface plate 22 adjacent the rear end of hull section 18. An inner wall 32 joins ribs 28 and so that a chamber is formed around the inner periphery plate 22.

The plurality of hydraulic cylinders 26 are positioned at spaced intervals in the chamber formed by ribs 28 and 30 and wall 32 along the periphery of plate 22. One end of each of cylinders 26 is anchored on rib 28, while the other ends of the hydraulic cylinders extend through openings 34 in rib 30. The piston rods 36 of hydraulic cylinders 26 also extend through openings 34 in rib 32. Piston rods 36 include flanged members 38 which mate with braces 14 in tunnel liner 12 when the piston rods are extended, thereby to move tunneling shield 10 forward with respect to the tunnel liner 12.

As shown in FIG. 3, the forward portion of hull section 18 slants rearwardly along the lower edges thereof. The upper forward portion of hull section 18 is cut away to provide a supporting structure for hood 20. A hoop or bail 40 is affixed to the lower forward edges of hull section 18 and extends into the cut away area of hull section 18 for supporting hood 20 in a manner hereinafter described. The forward portion of hull section 18 also includes a plurality of divider plates which are used to guide the segments of the hood during their extension and retraction. Divider plates 42 lie between each of the hood segments and on either side thereof. Referring initially to FIG. 3, a crosssectional view of the forward portion of hull section 18, the forward edge of divider plate 42 is secured to hoop 40, as by welding, by a notch provided for that purpose. The rear edge of the divider plate 42 is affixed to rib 28, while a flange 44 extending from the rear edge of the divider plate is affixed to wall 32. The other divider plates 42 incorporated in the structure may be affixed to hull section 18in a similar manner.

Because the forward portion of hull section 18 slants rearwardly in the lower portions thereof, the portion 28A of rib 28 to which the divider plates 42A, positioned along the sides of hull section 18, are attached may be displaced rearwardly so as to insure that the divider plates are properly anchored to hull section 18.

The divider plates 42 may be additionally fixed and supported on hull section 18 by gussets 46 attached to hoop 40 and the plates, as shown in FIGS. 3 and 4, and gussets 48 attached to wall 32 and flanges 44, as shown in FIGS. 3 and 5.

Hood 20 is comprised of a plurality of hood segments 50 mounted between divider plates 42. In the presently preferred embodiment of the invention, nine hood segments occupy a semicircular portion of the upper periphery of hull section 18. It will be appreciated that other numbers and configurations of hood segments may be used if desired. Each of hood segments 50 includes a hollow forward end portion 52 and a rearward end trail 54 which overlaps plate 22. A typical hood segment 50 is shown in longitudinal cross section in FIG. 2 and in lateral cross section in FIG. 6. The outer surface of hood segment 50 may comprise a single metallic sheet 56 which forms both trail 54 and the outer surface of portion 52. Additionally, as shown most clearly in FIG. 6, hollow end portion 52 includes an inner wall 58 connected to sheet 56 by sides 60 and 62 so that the portion 52 of hood segment 50 is generally trapezoidal in cross section configuration. As shown in FIGS. 4 and 6, sides 60 and 62 may be bent so as to allow portion 52 to clear gussets 46. Inner wall 58 rests on hoop 40. The end of portion 52 is closed by plate 64.

Because the hood segments 50 on the top of hull section 18 are required to bear the weight of the soil and overburden when extended, they may be made smaller and more rigid in construction so as to have a high beam strength for resisting deflection by such forces. The hood segments 50 of the sides of hull section 18 being subjected to less force by the over burden may be made larger, as shown in FIG. 4.

A hydraulic cylinder 66 is positioned inside each hollow portion 52 of hood segments 50 as shown in FIG. 2 for extending and retracting the hood segments. Each of the hydraulic cylinders are anchored to hull section 18 by brackets 68 affixed to rib 28. Bracket 68 and hydraulic cylinders 66 are linked by pin 70. The piston rod 72 of hydraulic cylinder 66 is also linked to portion 52 by a suitable bracket and pin 74.

To assist in the extension and retraction of hood segments 50, guiding ways are provided on divider plates 42. Specifically, and as shown in FIG. 6, sides 60 and 62 of hollow portion 52 have bearing strips 76 affixed thereto. A plurality of longitudinally spaced pins 78 inserted through divider plates 42 coact with bearing strips 76 to assist in the movement of hood segments 50.

FIG. 7 shows, in schematic form, a typical hydraulic system 80 which may be employed in tunneling shield 10. The hydraulic system includes the source of hydraulic fluid pressure, such as pressure pump 82. Pressure pump 82 is connected to two parallel hydraulic control circuits 84 and 86 which control the operation of hydraulic cylinders 26 and 66, respectively.

Hydraulic control circuit 84 includes master control valve 88 connected to pump 82 and hydraulic fluid reservoir 83 by means of pressure lines 90 and 92, respectively. One output line 94 of master control valve 88 is connected to hydraulic cylinders 26 ahead of the piston. Output line 94 may contain pressure gauge 95. The other output line 96 of master control valve 88 is connected to a plurality of individual control valves 98 which permit individual operation of hydraulic cylinders 26, if desiredv Control valves 98 are connected to hydraulic cylinders 26 by hydraulic lines 100 which provide pressurized fluid behind the piston of the cylinders. Control valves 98 are connected to reservoir 83 by return line 11].

Hydraulic control circuit 86 includes master control valve 102 connected to pump 82 by pressure line 104. The output line of master control valve 102 is connected to a plurality of control valves 108 which permit the extension and retraction of individual ones of hydraulic cylinders 66 and hood segments 50. Control valves 108 are connected to cylinders 66 by hydraulic lines 112 which supply fluid behind the pistons of hydraulic cylinders 66 and by fluid lines 116 which supply fluid ahead of the pistons of cylinders 66. Control valves 108 are connected to reservoir 83 by return lines 118 and 106. Master control valve 102 contains a pressure relief means 117 connected to fluid return line 106 which prevents excessive pressures from developing in hydraulic control circuit 86.

The sequence of operation of tunneling shield 10 may be described by starting at the commencement of an excavating operation. At the initiation of such operation, the rear of hull section 18 is in abutment with the last section of tunnel liner 12 and hood segments 50 are retracted with the forward edges of portions 52 against the working face of the tunnel. To begin an excavating operation, master control valve 102 is actuated to extend piston rods 72 of hydraulic cylinders 66 and extend hood segments 50 to drive portions 52 into the working face to form the semicircular shield shown in phantom in FIG. 2, beneath which the excavation may occur.

Any tendency of hood segments 50 to deflect sideways as they are driven forward, due to encounters with rocks or the like, is prevented by divider plates 42 which lie on either side of the hood segments. Any tendency of the hood segments 50 to deflect downward is prevented by the abutment of inner wall 58 on hoop 40 and by the coaction of slides 76 and pins 78 mounted on divider plates 42. Any tendency of the hood segments to deflect upward is prevented by trail 54 which lies along plate 22. The hood segments are thus driven forward in a true and aligned manner.

In the event large boulders are encountered by one or more of the hood segments 50 as they are driven forward, hood segments 50 may be individually controlled by valves 108 so as to move each segment forward to the maximum possible extent until such boulders are removed. FIG. 1 shows tunneling shield 10 with a single hood segment 52 extended.

In the event the working face of the tunnel comprises rock or other hard substances, the rock face may be drilled and dynamited prior to moving the hood segments forward. Hydraulic cylinder 66 and the associated fluid lines 112 and 116 are protected from the flying rock by inner wall 58 of portion 52 so that such blasting may be carried out without damage to the hydraulic apparatus. Hydraulic cylinders 26 and hydraulic lines 94 and 100 are likewise protected by wall 32.

After hood segments 50 have been driven forward, the portion of the work face beneath the hood segments is excavated by mechanical or manual means. The soil is removed from the tunnel through hull section 18 and tunnel liner 12.

When the work face has been completely excavated below the hood, master control valve 88 is operated to extend piston rods 36 so as to move hull section 18 forward. For this purpose, flanged members 38 are moved into abutment with braces 14 so that as the piston rods 36 are extended rearwardly, hull section 18 is moved forward. At the same time, master control valve 102 may be operated to retract hood segments 50 as hull section 18 moves forward so that the tips of portions 52 remain in contact with the working face of the tunnel as hull section 18 slides under hood segments 50.

Master control valve 88 and 102 may be interconnected to automatically provide for the retraction of hood segments 50 as piston rods 36 are extended, if desired. Hydraulic cylinders 26 may be individually operated by valves 98 to insure that hull section 18 is advanced in an aligned manner along the bore of the tunnel.

When piston rods 36 have been extended to the maximum extent and hull section moved forward a like amount, the piston rods may be retracted and a new section of tunnel liner 12 inserted along the bore of the tunnel.

The above described operation is then repeated to provide further excavation of the tunnel.

1n the foregoing drawing and specification, there has been set forth a preferred embodiment of the invention; and although specific terms have been employed, they are used in a generic and descriptive sense only, and not for the purposes of limitation. Various other modes of carrying out the invention are contemplated as being within the scope of the following claims, particularly pointing out and distinctly claiming the subject matter which is regarded as the invention.

1 claim:

1. A tunneling shield comprising, a longitudinally extending hull section; a segmented hood peripherally mounted at one end of the hull section for abutting the working face of a tunnel, said hood comprised of a plurality of laterally adjacent elongated hollow segments positioned for longitudinal extension with respect to said hull section, each of said segments having a closed forward end and being adapted to receive a hydraulic cylinder therewithin; and a hydraulic cylinder disposed within each of said hood segments when the latter are in an unextended position, said hydraulic cylinders being coupled between the respective hood segment and said hull section for selectively extending and retracting said hood segments to provide a shield above the working face of the tun nel.

2. The tunneling shield of claim 1 wherein said hull section includes a plurality of divider plates affixed thereto and positioned between adjacent hood segments to assist in the exten sion and retraction of said hood segments.

3. The tunneling shield of claim 2 wherein each of said hood segments has a pair of longitudinally extending sides forming portions of said closed forward end, said sides lying adjacent said divider plates and having means engaging said divider plates for preventing deflection of the hood segments during the extension and retraction thereof.

4. The tunneling shield of claim 3 wherein said longitudinally extending sides of said hood segments include slide means engaging projections on said divider plates for preventing deflection of the hood segments during the extension and retraction thereof.

5. The tunneling shield of claim 1 wherein said hull section is at least partially circular in cross-sectional configuration and wherein said hollow hood segments are of generally trapezoidal cross-sectional configuration, said hood segments being located along the circular portion of the periphery of said hull section.

6. The tunneling shield of claim 1 wherein said hollow hood segments are positioned along the upper peripheral portion of said hull section, the segments locate-d on the top of said hull section having a smaller cross-sectional area and greater beam strength than the segments located along the sides of said hull section.

7. The tunneling shield of claim 1 wherein said hull section lies along the bore of the tunnel in axial alignment with a tunnel liner lining the bore of the excavated tunnel and wherein said tunneling shield includes hydraulic means mounted on the rear of said hull section for engaging said tunnel liner to move said tunneling shield with respect to said tunnel liner. 

1. A tunneling shield comprising, a longitudinally extending hull section; a segmented hood peripherally mounted at one end of the hull section for abutting the working face of a tunnel, said hood comprised of a plurality of laterally adjacent elongated hollow segments positioned for longitudinal extension with respect to said hull section, each of said segments having a closed forward end and being adapted to receive a hydraulic cylinder therewithin; and a hydraulic cylinder disposed within each of said hood segments when the latter are in an unextended position, said hydraulic cylinders being coupled between the respective hood segment and said hull section for selectively extending and retracting said hood segments to provide a shield above the working face of the tunnel.
 2. The tunneling shield of claim 1 wherein said hull section includes a plurality of divider plates affixed thereto and positioned between adjacent hood segments to assist in the extension and retraction of said hood segments.
 3. The tunneling shield of claim 2 wherein each of said hood segments has a pair of longitudinally extending sides forming portions of said closed forward end, said sides lying adjacent said divider plates and having means engaging said divider plates for preventing deflection of the hood segments during the extension and retraction thereof.
 4. The tunneling shield of claim 3 wherein said longitudinally extending sides of said hood segments include slide means engaging projections on said divider plates for preventing deflection of the hood segments during the extension and retraction thereof.
 5. The tunneling shield of claim 1 wherein said hull section is at least partially circular in cross-sectional configuration and wherein said hollow hood segments are of generally trapezoidal cross-sectional configuration, said hood segments being located along the circular portion of the periphery of said hull section.
 6. The tunneling shield of claim 1 wherein said hollow hood segments are positioned along the upper peripheral portion of said hull section, the segments located on the top of said hull section having a smaller cross-sectional area and greater beam strength than the segments located along the sides of said hull section.
 7. The tunneling shield of claim 1 wherein said hull section lies along the bore of the tunnel in axial alignment with a tunnel liner lining the bore of the excavated tunnel and wherein said tunneling shield includes hydraulic means mounted on the rear of said hull section for engaging said tunnel liner to move said tunneling shield with respect to said tunnel liner. 